74 A SUMMER IN GREENLAND 
rocks ejected from some old volcano in the imme- 
diate neighbourhood. 
The peculiar construction of Lichens renders 
them less dependent than other plants upon the 
nature of the substratum on which they grow. 
As films of dull black they dapple the grey sur- 
faces of the gneiss, while other species produce a 
harmony of orange, yellow, and grey. On stony 
ground, among bosses of protruding rock and 
mixed with prostrate or tufted shrubs of the heath 
vegetation, large cushions of grey Lichens which 
whendrycrumble to the touch, the flat, deeply lobed 
fronds of a bright yellow species, and the clumps 
of erect branches of stouter forms, sometimes tipped 
with small scarlet balls, give light and brightness 
to the duller background. 
The Botany of Greenland is too wide a subject 
for more than a passing reference in these pages; 
it is intensely interesting to the botanist not only 
because of the richness of the flora, but also 
on account of its past history,—the relation of 
the vegetation of to-day to that which preceded the 
Glacial period, and the routes by which the pioneers 
of the present plant population arrived. 
A certain emotional influence is produced by the 
heath-covered hill-sides and swampy lowlands, by 
the scattered colonies of more brilliant flowers on 
the drier rock-strewn regions of this treeless land 
for the perception of which no knowledge of 
natural science is needed, and even the layman’s 
sense of wonder is stirred when he considers what 
this display signifies as a triumph of the forces of 
life over adverse physical conditions. 
